DIY 27mm Tool
Here are a few pics to show how to get the 27mm selector cover removed without a 27mm tool...
*edit* -- I have been contacted and informed that this method can cause the selector cover to crack if it is in real tight. The forces are going to be concentrated into smaller contact spots, which can crack the cover. There are 3 other versions of tools that will work better at the bottom of the page!
You can use just about any old bolt, the bigger the better, and then an assortment of washers and small nuts and so on to use as shims. This is a pic of some random stuff laying about the garage.
An old rusty 19mm bolt, the lockrings from a Pelolok bolt kit, half a dozen washers for the 13mm bolts used around the 020 case, a MK2 rear shock spring cap perch washer, an old square nut, and a couple random washers.... something in there should do the trick.
This works fairly well, the bolt turns a bit then gets wedged in place. As long as the head of the bolt stays pushed in flat against the selector cap, this would work...
Using the square nut, it fits much better than a couple stacked washers, and shims the bolt better. 3 nuts slightly thinner would be ideal, but this works as well. I could find 3 nuts and hit them on the grinder wheel to fit them perfectly if desired....
I found the nut for the 19mm bolt, and it is taller, so it fits better into the hex head.... weld the nut in place, shim it with 3 smaller nuts as shown above, tack those nuts in place and you have a tool for the selector cap, and the green timing check plug!
From Greg_J via VWVortex:
1" square tubing, ground to fit:
From Dave F.
Home Depot nuts & bolts stock #3242
From Erik C.
part # 91034A125 from McMaster-Carr, only $4.38